A majority of conventionally used refrigerating machines for a room temperature range such as a refrigerator, a freezer, and an air conditioner utilize the phase transition of a gaseous refrigerant such as CFC (chlorofluorocarbon) or a CFC substitute. Recently, the destruction of the ozone layer caused by the discharge of CFC has been revealed, and there have been concerns regarding the influence to the global warming in conjunction with the discharge of a CFC substitute. For this reason, it is strongly desired to develop an innovative refrigerating machine that is pollution-free, has a high heat-transfer capability, and replaces a refrigerating machine that uses a gaseous refrigerant such as CFC or a CFC substitute.
Due to the above-described background, the refrigerating technique that has recently been caught attention is the magnetic refrigerating technique. Among magnetic substances, there is a substance that exhibits so-called a magneto-caloric effect, in which when a magnetic field applied to the magnetic substance changes in magnitude, the magnetic substance changes its own temperature in accordance with the magnitude change of the magnetic field. The refrigerating technique using the magneto-caloric effect to transfer heat is referred to as the magnetic refrigerating technique.
As a magnetic refrigerating machine applying the magneto-caloric effect, there is a magnetic refrigerating machine utilizing heat conduction of a solid substance to transfer heat as described in Patent Document 1 below, for example. This magnetic refrigerating machine transfers heat by the following configuration.
The positive magnetic bodies that raise their own temperature upon the application of a magnetic field thereto and the negative magnetic bodies that lower their own temperature upon the application of a magnetic field thereto are alternately arranged in one direction at a predetermined interval. A magnetic body block is formed by a pair of the positive and negative magnetic body. A magnetic body unit is formed by arranging a plurality of the magnetic body blocks lined up in one direction annularly. A magnetic unit is formed by arranging permanent magnets on a rotary body having a hub shape, in which the inner diameter and the outer diameter are almost equal and which is concentric with the magnetic body unit. A heat-conductive member, that is inserted into and pulled out of a space between the positive and negative magnetic bodies, is arranged so as to freely slide between the positive and negative magnetic bodies.
The magnetic unit in which the permanent magnets are disposed is arranged so as to face the magnetic body unit and rotate relative to the magnetic body unit. The heat-conductive member that is inserted into and pulled out of the space between the positive and negative magnetic bodies is set to rotate relative to the magnetic body unit. The rotation of the magnetic unit causes a magnetic field to be simultaneously applied to or removed from the positive and negative magnetic bodies. Also, the heat-conductive member is inserted into or pulled out of the space between the positive and negative magnetic bodies arranged in the rotational direction. The rotation of the permanent magnets and the heat-conductive members causes the heat generated by the magneto-caloric effect of the magnetic bodies to be transferred via the heat-conductive member in one direction in which the magnetic bodies are arranged.